Implantable drug infusion devices are well known in the art. These devices typically include a medication reservoir within a generally cylindrical housing. Some form of fluid flow control is also provided to control or regulate the flow of fluid medication from the reservoir to the outlet of the device for delivery of the medication to the desired location in a body, usually through a catheter. These devices are used to provide patients with a prolonged dosage or infusion of a drug or other therapeutic agent.
Active drug infusion devices feature a pump or a metering system to deliver the drug into the system of a patient. An example of such a drug infusion pump currently available is the Medtronic SynchroMed programmable pump. Additionally, U.S. Pat. No. 4,692,147 (Duggan), U.S. Pat. No. 5,840,069 (Robinson), and U.S. Pat. No. 6,036,459 (Robinson), assigned to Medtronic, Inc., Minneapolis, Minn., disclose body-implantable electronic drug administration devices comprising a peristaltic (roller) pump for metering a measured amount of drug in response to an electronic pulse generated by control circuitry associated within the device. Each of these patents is incorporated herein by reference in their entirety for all purposes. Such devices typically include a drug reservoir, a fill port, a peristaltic pump having a motor and a pumphead to pump out the drug from the reservoir, and a catheter port to transport the drug from the reservoir via the pump to a patient's anatomy. The drug reservoir, fill port, peristaltic pump, and catheter port are generally held in a housing, or bulkhead. The bulkhead typically has a series of passages extending from the drug reservoir and through the peristaltic pump that lead to the catheter port, which is typically located on the side of the housing. The peristaltic pump comprises a pumphead having rollers, a race or cavity defined by the bulkhead, and a pump tube that is threaded or inserted between the rollers and the race. The peristaltic pumps use the rollers to move a drug through the pump tube from the drug reservoir to the catheter port. The drug is then pushed by the pump through a catheter connected to the catheter port, and is delivered to a targeted patient site from a distal end of the catheter.
In the assembly or fabrication of peristaltic pumps, the pump tube must be installed in the device. More specifically, the pump tube must be threaded or inserted between the pump rollers and a race, and this installation is typically done as the pumphead is rotated. In conventional peristaltic pumps, the pump rollers can impede the installation of the pump tube between the rollers and the race. Impeding the insertion of the pump tube between the rollers and the race can increase manufacturing costs, and decrease ease and flexibility of manufacturing, as well as give rise to the potential for excessive load and/or damage to the pump tube during installation between the rollers and the race. It is an object of the present invention to provide an implantable drug infusion device which reduces or eliminates some or all of the difficulties in conventional devices and their manufacture.
It is an object of the present invention to provide an implantable drug infusion device which reduces or wholly overcomes some or all of the difficulties inherent in prior known devices. Particular objects and advantages of the invention will be apparent to those skilled in the art, that is, those who are knowledgeable or experienced in this field of technology, in view of the following disclosure of the invention and detailed description of preferred embodiments.